Properties of a Ni-FUSI gate formed by the EBV method and one-step RTA

Nickel fully silicided（Ni-FUSI） gate material has been fabricated on a HfO2 surface to form a Ni-FUSI gate/HfO2/Al（MIS） structure by using an ultra-high vacuum e-beam evaporation（EBV） method followed by a one step rapid thermal annealing（RTA） treatment.X-ray diffraction（XRD） and Raman spectroscopy were used to reveal the microstructures and electrical properties of the MIS structure.Results show that a one step post RTA treatment is enough to promote the full reaction of nickel silicide,compared with multiple RTA treatments. Furthermore,the HfO2 gate dielectric film is sensitive to heat treatment,and multiple RTA treatments can damage the electrical properties of the HfO2 film rather than improve them.By optimization of the sample fabrication technique,the MIS capacitor produces good high-frequency capacitance-voltage curves with a hysteresis of 30 mV, a work function of about 5.44-5.53 eV and leakage current density of only 1.45×10~（-8） A/cm~2 at -1V gate bias.